Definition
Anal cancer is cancer that starts in the anus. It’s a canal at the end of the colon. The sphincter is a muscular ring that allows for bowel movements.
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Causes
Cancer is when cells in the body split without control or order. These cells go on to form a growth or tumor. The term cancer refers to harmful growths. These growths attack nearby tissues. They also spread to other parts of the body. It’s not clear exactly what causes these problems. It’s likely a mix of genes and the environment.
Anal cancer is linked to human papillomavirus (HPV) infection.
Risk Factors
Your chances of anal cancer are higher for:
- Anal intraepithelial neoplasia—precancerous changes in cells
- HIV infection
- Having many sex partners
- Receiving anal sex
- Smoking
- Genital warts
- Immune system problems because of the medicines you take
- Cervical dysplasia or cervical cancer
Symptoms
You may not notice any symptoms at first. When present, anal cancer may cause:
- Passing of blood or mucus
- Pain or pressure
- Feeling of a mass
- Itching
- Change in bowel habits
Diagnosis
The doctor will ask about your symptoms and health history. You may also have:
- Blood tests
- Anoscopy
- Sigmoidoscopy
- Imaging tests such as:
- Biopsy —a sample of anal tissue is tested in a lab
The exam and your test results will help find out the stage of cancer you have. Staging guides your treatment. Anal cancer is staged from 0-4. Stage 0 is a very localized cancer. Stage 4 is a spread to other parts of the body.
Treatment
Anal cancer is treated with more than one method. Sometimes they’re combined. This may include:
Chemotherapy
Chemotherapy is the use of drugs to kill cancer cells. It may given by mouth, shots, or IV. The drugs enter the bloodstream and travel throughout the body.
Radiation Therapy
Radiation therapy is the use of radiation to kill cancer cells and shrink tumors. It may be given at the same time as chemotherapy. This may help avoid surgery.
Scar tissue may form in the anus, keeping the anal sphincter from working properly. In addition, damage may occur that results in chronic rectal bleeding.
Surgery
Local Resection
Local resection allows for the removal of small, localized cancers. A small border of healthy tissue around the cancer will also be removed. Local resection preserves anal function.
Abdominoperineal Resection
An abdominoperineal resection (APR) is a surgery to remove the anus and rectum. It’s an option if the cancer cannot be treated or returns. APR results in the need for a colostomy. A path for solid waste to pass from the body is made through the belly wall. A special bag is needed to collect the waste.
Prevention
To lower your chances of anal cancer:
- Talk to your doctor about the HPV vaccine.
- Practice safe sex to lower your chances of HPV or HIV infection.
- See your doctor if you have any problems or notice any changes in your anus.
RESOURCES:
American Cancer Society
https://www.cancer.org
United Ostomy Associations of America
https://www.ostomy.org
CANADIAN RESOURCES:
Canadian Cancer Society
https://www.cancer.ca
Ostomy Canada Society
https://www.ostomycanada.ca
REFERENCES:
Anal cancer. American Cancer Society website. Available at: https://www.cancer.org/cancer/anal-cancer.html. Accessed January 29, 2021.
Anal cancer. EBSCO DynaMed website. Available at: http://www.dynamed.com/topics/dmp~AN~T114194/anal-treatment-pdq#_1. Accessed January 29, 2021.
Anal cancer treatment (PDQ)—patient version. National Cancer Institute website. Available at: https://www.cancer.gov/types/anal/patient/anal-treatment-pdq. Accessed January 29, 2021.
Joura EA, Leodolter S, Hernandez-Avila M, et al. Efficacy of a quadrivalent prophylactic human papillomavirus (types 6, 11, 16, and 18) L1 virus-like-particle vaccine against high-grade vulval and vaginal lesions: a combined analysis of three randomised clinical trials. Lancet. 2007;369(9574):1693-1702.
Uronis HE, Bendell JC. Anal cancer: an overview. Oncologist. 2007;12(5):524-534.
Last reviewed September 2020 by EBSCO Medical Review Board Mohei Abouzied, MD, FACP Last Updated: 1/29/2021